My project involves the subject of Electrolysis, or more specifically, the electroplating of iron. This subject of chemistry involves electricity to facilitate chemical reactions using electrons.
There are two particular processes that materials go through in electrolysis: oxidation and reduction. Oxidation is the process of the removal of electrons from a substance, usually a metal, and the subsequent increase in charge of the substance. The substance that is being oxidized is known as the anode and therefore attracts anions, or negatively charged ions. Corrosion is where metal is oxidized and the mass of the metal decreases as the metal breaks down into oxidized compounds and salts, which break off from the larger piece of metal. Corrosion, or rusting, can be attributed to repeated or constant exposure to air, water, or both. Another version of corrosion is pitting, which is localized corrosion that corrodes a specific spot of the metal and creates small holes in the metal, reducing structural integrity. Both rusting and pitting are examples of corrosion and oxidation.
Reduction is the exact opposite reaction and is taking place on the other substance or metal in an electrolysis reaction. Reduction adds electrons onto a substance and reduces the charge of the substance or metal. Continuing the pattern of reduction being the opposite of oxidation, the substance being reduced is known as the cathode, the opposite of the anode. It attracts cations, the opposite of anions, which are positively charged ions.
If both of these reactions are taking place in a controlled environment, it’s called an electrolytic cell. A basic electrolytic cell contains two electrodes, one of which is the anode that is being oxidized and having anions formed. The other is a cathode which is being reduced and having cations formed. Both electrodes are immersed in an electrolyte substance that makes the electrodes more conductive. Electrolytes are also known as salt bridges. It’s called a “salt” bridge because it usually consists of compounds containing combinations of alkali metals and halides, which form salts. It’s known as a bridge because it connects the two electrodes completing the circuit along with a wire and allowing a flow of cations to the cathode and anions to the anode. The final part of an electrolytic cell is the aforementioned wire that connects the electrodes and completes the circuit with the previously defined salt bridge. Completing a circuit simply means that electric current can travel in a circuit without going back and forth across somewhere the current has already crossed during one circuit.
Electroplating is the specific process of oxidizing the anode metal and plating the cathode metal with the oxidized metal. Electroplating takes place in an electrolytic cell-type environment, if natural or engineered. Electroplating as a process was designed to make the plated metal resistant to corrosion and increase the life span operating conditions of the metal product. Corrugated steel roofing on barns, shacks, or other structures is electroplated in order to help the metal roof last from the elements. However, this is not a permanent solution and electroplated products will often begin to deteriorate after a certain amount of time, depending on the conditions in which the product has been kept.
Many additional uses and applications of electroplating exist in the commercial and manufacturing industries. Aluminum electroplating is used on climbing carabiners. This makes the carabiner much more resistant to corrosion and wear due to weather conditions, greatly improving it’s options in use. Electroplating the aluminum onto the carabiner also makes the metal a lot stronger significantly increasing the weight the carabiner can hold.3
Another more widely known use is galvanization. Galvanization is the specific electroplating of a thin layer of zinc or tin to a metal surface. Zinc or tin metals are specifically used, as both are highly resistant to corrosion. Galvanization is used to protect corrugated roofing, galvanized buckets, and many other metal products.4 Galvanization was named for Luigi Galvani, an Italian physician, who experimented with bioelectricity in the 18th century and came up with various theories on the relationship between electricity and animals.5 However, he did not do much on electricity and metal. Stanislas Sorel, a French engineer, first patented the first process of Galvanization in 1837.6
Colin Garfield Fink is known as the father of electroplating. During the early 20th century, he worked with chromium trying to find many uses for it. He eventually ended up trying to cover his iron bath basin in chromium. He found that sulfate ions from sulfuric acid were sufficient at electroplating the chromium. This discovery led to the process of “chroming” different things such as tire rims and other car accessories.8
Modern research of electrolysis is concentrating in the area of cleaning up wastewater. To make a very long article short, the idea is to use the process of electrolysis to remove harmful chemicals and heavy metals from wastewater in order to not further contaminate the environment.9
Procedure
The basic point of this experiment was to determine which substance (salsa, vinegar, or water) would function better as an electrolyte substance. To begin with, I put about 50 ml of each substance in 3 100 ml beakers, with the vinegar and salsa as test substances and water as a control. Both the water and vinegar, incidentally, were ingredients in the salsa. I then placed one iron nail in each beaker and connected the negative terminal of a 12 V motorcycle battery to the nail and the positive terminal to a copper wire immersed in the electrolyte substance. Making sure not to let anything connected to the negative terminal touch the positive terminal, I left all three beakers overnight.
Results
The initial observations, after a mere 5 minutes of letting the processes happen, were promising. Slow bubbles were forming in the salsa and when I removed the nail from all three to observe any changes, discoloration was apparent where the nail was in the substance.
Before I reveal the results of my experiment, I must confess that at some point during the 24 hour period that I left the three beakers alone, one or more of the beakers were bumped or jostled, resulting in the two electrodes touching, which may or may not have contaminated the experiment.
However, barring some accelerated or skewed outcome, here are my results
Going from left to right, or most effective to least effective, the beakers are as follows: Vinegar, Salsa, Water.
The masses of the before nail and the new nail are also as follows:
Vinegar Before: 7.47g
Vinegar After: 4.45g
Salsa Before: 6,29g
Salsa After: 4.44g
Water Before: 4.56g
Water After: 4.47g
Final Observations: All three beakers smelled faintly of something rotting.
Vinegar: The vinegar appeared to look like brownish water with what appeared to be congealed substances not dissimilar from sewage. This result may have been from the electrodes touching. The copper wire was no where to be found, and the alligator clip connected it was destroyed and non-reusable. At the bottom of the substance were small black masses that appeared to be corroded iron.
Water: The water had turned a yellowish-brownish color. The bottom half of the liquid had a dark reddish-blackish substance that I assumed to be iron oxide, from the water contacting the iron nail for 24 hours. The copper wire was also coated in a blackish substance, which was the oxidized iron being electroplated onto the copper.
Salsa: The salsa itself had a dark, almost burnt vein of black substance going through it, which I interpreted as the place where the metals had reacted, or quite possible touched causing arcing, sparks and heat, therefore cooking the salsa. The alligator clips, like in the vinegar, were destroyed as well. Additionally, the copper wire was also coated in a blackish substance, which I took to be the iron.
Conclusions
Despite expectations and initial observations, the vinegar was a far more effective and faster-acting electrolyte than salsa or water. Although all three lost mass, and the salsa and vinegar lost mass visibly, the vinegar clearly did far more in the amount of time given.
References
1. Buthelezi, Thandi, and Laurel Dingrando, and Nicholas Hainen, and Cheryl Wistrom, and Dinah Zike. Chemistry: Matter and Change. New York, 2008.
Table of Contents
Electrolysis of Iron Nails
Hunter
Introduction
My project involves the subject of Electrolysis, or more specifically, the electroplating of iron. This subject of chemistry involves electricity to facilitate chemical reactions using electrons.
There are two particular processes that materials go through in electrolysis: oxidation and reduction. Oxidation is the process of the removal of electrons from a substance, usually a metal, and the subsequent increase in charge of the substance. The substance that is being oxidized is known as the anode and therefore attracts anions, or negatively charged ions. Corrosion is where metal is oxidized and the mass of the metal decreases as the metal breaks down into oxidized compounds and salts, which break off from the larger piece of metal. Corrosion, or rusting, can be attributed to repeated or constant exposure to air, water, or both. Another version of corrosion is pitting, which is localized corrosion that corrodes a specific spot of the metal and creates small holes in the metal, reducing structural integrity. Both rusting and pitting are examples of corrosion and oxidation.
Reduction is the exact opposite reaction and is taking place on the other substance or metal in an electrolysis reaction. Reduction adds electrons onto a substance and reduces the charge of the substance or metal. Continuing the pattern of reduction being the opposite of oxidation, the substance being reduced is known as the cathode, the opposite of the anode. It attracts cations, the opposite of anions, which are positively charged ions.
If both of these reactions are taking place in a controlled environment, it’s called an electrolytic cell. A basic electrolytic cell contains two electrodes, one of which is the anode that is being oxidized and having anions formed. The other is a cathode which is being reduced and having cations formed. Both electrodes are immersed in an electrolyte substance that makes the electrodes more conductive. Electrolytes are also known as salt bridges. It’s called a “salt” bridge because it usually consists of compounds containing combinations of alkali metals and halides, which form salts. It’s known as a bridge because it connects the two electrodes completing the circuit along with a wire and allowing a flow of cations to the cathode and anions to the anode. The final part of an electrolytic cell is the aforementioned wire that connects the electrodes and completes the circuit with the previously defined salt bridge. Completing a circuit simply means that electric current can travel in a circuit without going back and forth across somewhere the current has already crossed during one circuit.
Electroplating is the specific process of oxidizing the anode metal and plating the cathode metal with the oxidized metal. Electroplating takes place in an electrolytic cell-type environment, if natural or engineered. Electroplating as a process was designed to make the plated metal resistant to corrosion and increase the life span operating conditions of the metal product. Corrugated steel roofing on barns, shacks, or other structures is electroplated in order to help the metal roof last from the elements. However, this is not a permanent solution and electroplated products will often begin to deteriorate after a certain amount of time, depending on the conditions in which the product has been kept.
Many additional uses and applications of electroplating exist in the commercial and manufacturing industries. Aluminum electroplating is used on climbing carabiners. This makes the carabiner much more resistant to corrosion and wear due to weather conditions, greatly improving it’s options in use. Electroplating the aluminum onto the carabiner also makes the metal a lot stronger significantly increasing the weight the carabiner can hold.3
Another more widely known use is galvanization. Galvanization is the specific electroplating of a thin layer of zinc or tin to a metal surface. Zinc or tin metals are specifically used, as both are highly resistant to corrosion. Galvanization is used to protect corrugated roofing, galvanized buckets, and many other metal products.4 Galvanization was named for Luigi Galvani, an Italian physician, who experimented with bioelectricity in the 18th century and came up with various theories on the relationship between electricity and animals.5 However, he did not do much on electricity and metal. Stanislas Sorel, a French engineer, first patented the first process of Galvanization in 1837.6
Colin Garfield Fink is known as the father of electroplating. During the early 20th century, he worked with chromium trying to find many uses for it. He eventually ended up trying to cover his iron bath basin in chromium. He found that sulfate ions from sulfuric acid were sufficient at electroplating the chromium. This discovery led to the process of “chroming” different things such as tire rims and other car accessories.8
Modern research of electrolysis is concentrating in the area of cleaning up wastewater. To make a very long article short, the idea is to use the process of electrolysis to remove harmful chemicals and heavy metals from wastewater in order to not further contaminate the environment.9
Procedure
The basic point of this experiment was to determine which substance (salsa, vinegar, or water) would function better as an electrolyte substance. To begin with, I put about 50 ml of each substance in 3 100 ml beakers, with the vinegar and salsa as test substances and water as a control. Both the water and vinegar, incidentally, were ingredients in the salsa. I then placed one iron nail in each beaker and connected the negative terminal of a 12 V motorcycle battery to the nail and the positive terminal to a copper wire immersed in the electrolyte substance. Making sure not to let anything connected to the negative terminal touch the positive terminal, I left all three beakers overnight.
Results
The initial observations, after a mere 5 minutes of letting the processes happen, were promising. Slow bubbles were forming in the salsa and when I removed the nail from all three to observe any changes, discoloration was apparent where the nail was in the substance.
Before I reveal the results of my experiment, I must confess that at some point during the 24 hour period that I left the three beakers alone, one or more of the beakers were bumped or jostled, resulting in the two electrodes touching, which may or may not have contaminated the experiment.
However, barring some accelerated or skewed outcome, here are my results
Going from left to right, or most effective to least effective, the beakers are as follows: Vinegar, Salsa, Water.
The masses of the before nail and the new nail are also as follows:
Vinegar Before: 7.47g
Vinegar After: 4.45g
Salsa Before: 6,29g
Salsa After: 4.44g
Water Before: 4.56g
Water After: 4.47g
Final Observations: All three beakers smelled faintly of something rotting.
Vinegar: The vinegar appeared to look like brownish water with what appeared to be congealed substances not dissimilar from sewage. This result may have been from the electrodes touching. The copper wire was no where to be found, and the alligator clip connected it was destroyed and non-reusable. At the bottom of the substance were small black masses that appeared to be corroded iron.
Water: The water had turned a yellowish-brownish color. The bottom half of the liquid had a dark reddish-blackish substance that I assumed to be iron oxide, from the water contacting the iron nail for 24 hours. The copper wire was also coated in a blackish substance, which was the oxidized iron being electroplated onto the copper.
Salsa: The salsa itself had a dark, almost burnt vein of black substance going through it, which I interpreted as the place where the metals had reacted, or quite possible touched causing arcing, sparks and heat, therefore cooking the salsa. The alligator clips, like in the vinegar, were destroyed as well. Additionally, the copper wire was also coated in a blackish substance, which I took to be the iron.
Conclusions
Despite expectations and initial observations, the vinegar was a far more effective and faster-acting electrolyte than salsa or water. Although all three lost mass, and the salsa and vinegar lost mass visibly, the vinegar clearly did far more in the amount of time given.
References
1. Buthelezi, Thandi, and Laurel Dingrando, and Nicholas Hainen, and Cheryl Wistrom, and Dinah Zike. Chemistry: Matter and Change. New York, 2008.2. “Electrolysis”. Wikipedia. < http://en.wikipedia.org/wiki/Electrolysis>
3. “Electroplating”. Wikipedia. < http://en.wikipedia.org/wiki/Electroplating>
4. “Galvanization”. Wikipedia. < http://en.wikipedia.org/wiki/Galvanization>
5. “Luigi Galvani”. Wikipedia. < http://en.wikipedia.org/wiki/Galvani>
6. “Stanislas Sorel”. Wikipedia. < http://en.wikipedia.org/wiki/Stanislas_Sorel>
7. No Author. Science: Aluminum Plating. 20 Aug. 1928. 29 Mar. 2010. <http://www.time.com/time/magazine/article/0,9171,881205-1,00.html>
8. No Author. Science: Fink’s Plate. 19 Aug. 1935. 29 Mar. 2010. <http://www.time.com/time/magazine/article/0,9171,848149,00.html>
9. No Author. Science: Technology Notes. 29 Dec. 1941. 29 Mar. 2010. <http://www.time.com/time/magazine/article/0,9171,772951,00.html>
10. Poon, Calvin and Thomas Brueckner. “Physicochemical Treatment of Wastewater-Seawater Mixture by Electrolysis”. Journal (Water Pollution Control Federation). Jan, 1975. < http://www.jstor.org/stable/25038597?seq=2&Search=yes&term=electrolysis&list=hide&searchUri=%2Faction%2FdoAdvancedSearch%3Fq0%3Delectrolysis%26f0%3Dall%26c0%3DAND%26q1%3D%26f1%3Dall%26c1%3DAND%26q2%3D%26f2%3Dall%26c2%3DAND%26q3%3D%26f3%3Dall%26wc%3Don%26sd%3D1970%26ed%3D2000%26la%3D%26jo%3D%26Search%3DSearch&item=1&ttl=1056&returnArticleService=showArticle&resultsServiceName=doAdvancedResultsFromArticle>